BiPAP settings and false inspiratory triggering

Snoredog,

Great analysis and thank you! It is starting to make sense finally, particularly the higher IPAP setting relative to the PSMax setting. Since I'm still having what appear to be hypopneas that should help lower the AHI.

I just tried 5 minutes with bilevel only, and it actually was triggering 100% of the time, no false inspiratory events. Perhaps biflex and my ugly mug are just flexible enough to produce a "spring event" and show a flow to the machine that suggests I'm inhaling when I actually am not doing anything. I was using 9/4.5, but now understand I can go much higher safely and hopefully the AHI will come way down. Interesting that I feel as good as I do with relatively high AHI. Makes me hopeful for even better results and energy. I actually like the sense of breathing with biflex off, which surprised me a bit.

Let me go at this more selectively and slowly and report back in about a week. Thanks again for taking the time to review the material and provide the education---it is very useful for me.

Peace

The machine was set on auto BiPAP w/ biflex.
IPAP max 12
EPAP min 6
PSMax 3

Here are the results:


I certainly get the least of what I will call "false inspiratory triggering" for lack of a better term, when the IPAP and EPAP pressures are the closest--which I guess means there is a lower likelihood of a leak or diaphgragmatic "bounce" looking like an inspiratory flow when it is not.

Aerophagia is way up overnight which is the primary reason I have a bilevel machine---to decrease or stop this side effect.

PeaceSleeper wrote: Perhaps biflex and my ugly mug are just flexible enough to produce a "spring event" and show a flow to the machine that suggests I'm inhaling when I actually am not doing anything.

Just remember if you ditch BiFlex to make sure you adjust the Rise Time to a moderate setting of 3 to start instead of the default of 1.

Thanks Christinequilts! I forgot about that---which you had noted in an earlier post. The issue appears to be more frequent with biflex turned on at any level.

It is a bit strange, but I think I may have a weird breathing pattern and may have developed it in the last 12 months. I tend to take a large breath with a long slow exhalation and then a pause which is sometimes pretty darn long before taking the next breath. I think this is a trained thing for me as almost a year ago when the sleep apnea was out of control, I also was having severe GERD and layngospasm and the breathing stopped cold for about 30-60 seconds depending on the severity of the episode. That went on for months until a couple of smart docs put it together and said---hey you have something (in the US anyway) called VCD or vocal cord dysfunction, but it is not idiopathic--it has a cause either in sinus drainage or reflux. Well reflux was the big winner. At the same time I did a lot of work on controlling hyperventilation because I was so air starved I would throw myself into a hyperventilation episode in the middle of the night. I must have read 3 books from Australia on hyperventiliation syndrome---not exactly what I was dealing with, but the breathing therapy for it was very helpful to raise PCO2 and to generally calm down. (And get O2 back to the old noggin.) My asthma was also very out of control at the same time, no surprise.

Anyway, long note probably not related.

I think I'm closing in pretty rapidly on something that will work for me. I do know that although my AHI number is lower on auto biflex last night, I actually feel worse due to the aerophagia, which produces severe mid-sternal and back pain and all the other usual wonderful features of gas in the GI tract. I am wide awake though!

Peace

Rise time: Rise time is inhalation time or time it takes you to "inhale", that timer needs to match your inhale time as closely as possible. It should go in 1/10th of second settings from 1 to 3 seconds. A lot of people end up around 1.7 to 1.8. Too long it will lag behind, too short it will cut you off before you completed your breath. Leave Biflex off or low and adjust rise time to match your breathing so it becomes more comfortable. Your AHI has dropped by half with those new settings.

Increase PS=4

You can see with PS=3 how EPAP pushed up IPAP in the beginning of that session then pulled it back down after therapy hour 1. You can also see in therapy hour 2 where IPAP went up to a 3cm PS to address those hypopnea without bringing up EPAP.

Work on getting the Rise timer set to your breathing, it should feel more comfortable by tweaking that setting to "match" your breathing. Getting all these things set correctly will help with the aerophagia more than anything, even lower pressure.

Note: Rise time should be something you adjust while awake. When set correctly, your breathing should be natural and smooth. Once you get all these settings dialed in, then you can use/increase Biflex for even more added comfort. Don't let Biflex "mask" the basic settings, get those down first then use Biflex.

Snoredog wrote:Rise time: Rise time is inhalation time or time it takes you to "inhale", that timer needs to match your inhale time as closely as possible. It should go in 1/10th of second settings from 1 to 3 seconds. A lot of people end up around 1.7 to 1.8. Too long it will lag behind, too short it will cut you off before you completed your breath.

I think you are mixing up Rise Time and IPAP max, which Respironics call Timed Inspirations in the Synchrony manual (VPAP also has IPAP min & IPAP max).
Rise time affects the time in transition from IPAP to EPAP and ranges from 1 to 6, corresponding to the tenths of a second (ie: 3=0.3 seconds rise time). When BiFlex is enabled, Rise Time is set to 3 (O.3 seconds...at least on Synchrony Lab models). IPAP Max or Timed inspirations ranges from 0.5 to 3.0 sec, increment of change: 0.1 second. Default setting is usually 3.0. I'm not familiar enough with autoBiPAP to know what screen he would need to look at for IPAP Max setting, but if he keeps feeling like IPAP is getting cut short and BiFlex/Rise Time are adjusted appropriately, you have to question if his IPAP Max could be mis-set.

On this M series AutoBiPAP machine, rise time refers to the number of milliseconds required to transition from EPAP to IPAP.

There are only 3 settings available---besides "off".
1 sets Rise Time to 200 msec
2 sets Rise Time to 300 msec
3 sets Rise Time to 400 msec

BiFlex and controlled rise time cannot be active at the same time.

I realized after this discussion that I am breathing quite deeply when I try to go to sleep, which I am fairly certain is causing the unpredictable flipping from EPAP to IPAP. When I relax more and breath more shallowly (and therefore a bit more rapidly) I can go for several minutes with no false flips.

I think that running in bilevel and slowly adding automated capabilities later makes sense. I did not have a good experience with the M series AutoCPAP because the pressure transitions or steps kept waking me up---fully awake. Something in my nervous system feedback loop is overly sensitive in this regard relative to the norm I suppose.

Aerophagia seems like a potentially complex item, but on the simple end of it I know pressures at 8 cm or above produce it in great volume.

[quote="PeaceSleeper"]On this M series AutoBiPAP machine, rise time refers to the number of milliseconds required to transition from EPAP to IPAP.

There are only 3 settings available---besides "off".
1 sets Rise Time to 200 msec
2 sets Rise Time to 300 msec
3 sets Rise Time to 400 msec

BiFlex and controlled rise time cannot be active at the same time.

I realized after this discussion that I am breathing quite deeply when I try to go to sleep, which I am fairly certain is causing the unpredictable flipping from EPAP to IPAP. When I relax more and breath more shallowly (and therefore a bit more rapidly) I can go for several minutes with no false flips.

I think that running in bilevel and slowly adding automated capabilities later makes sense. I did not have a good experience with the M series AutoCPAP because the pressure transitions or steps kept waking me up---fully awake. Something in my nervous system feedback loop is overly sensitive in this regard relative to the norm I suppose.

Aerophagia seems like a potentially complex item, but on the simple end of it I know pressures at 8 cm or above produce it in great volume.

Rest assured that the rise time is stated in milliseconds, not full seconds. More than one second does not make sense based on simple objective evidence---just breath in and out with the machine and feel how fast it transitions pressures---well under one second. This is not accounting for an end of expiration no flow situation. If I'm meditating I can breath with a prolonged delay after expiration, continuing for an hour, but I don't think the BiPAP cares---it is just looking for a state change(s) that indicate(s) inspiration. I don't know the details of the sensing devices and programming, nor all of the disease states this thing considers in its logic. I think we are talking about 2 different parameters and this machine has no such setting for inspiration timing.

There is no other provider or user accessible parameter related to inspiration timing, unless it is locked down in some secondary super-secret location in the menu system. This is not a BiPAP S/T, just a BiPAP. Such a parameter certainly does not exist in Encore Pro's machine prescription information system. In fact, Encore does not currently support the EPAP/IPAP rise time parameter, you have to go to the machine and enter provider mode to see the setting.

PeaceSleeper wrote:this machine has no such setting for inspiration timing.

Correct.

PeaceSleeper wrote:There is no other provider or user accessible parameter related to inspiration timing, unless it is locked down in some secondary super-secret location in the menu system. This is not a BiPAP S/T, just a BiPAP.

It's not hidden. You're correct that there's no inspiration timer to set in the BiPAP Auto (M series or "classic", either one.)

Just "rise time" if used in one of its bi-level modes without enabling bi-flex." And "bi-flex" if used in one of its modes that allows enabling bi-flex. As you already know, PeaceSleeper, with the BiPAP Auto, both features can't be used at the same time. Have to pick one or the other -- bi-flex OR rise time -- and set the operating mode accordingly to allow the one you want.

I personally like using bi-flex better than setting a rise time. The modes in which a rise time could be set felt rough to me. The longer I set the rise time (setting of "3") the better it felt; but never felt as smooth as when using bi-flex at "3". But each person is different...in treatment needs and/or comfort preference.

Snoredog wrote:
WHAT is the name of the parameter where it lists the 200-400msec values?

It gets confusing when they switch measurement units from brand to brand & even sometimes within brands over time, along with all the names for various settings too. It use to be if someone was talking about mSeconds, I knew they were talking about Rise Time on a VPAP (or whatever ResMed actually calls it), if they said 1-6, it was a Resprironic's BiPAP rise time, but I guess they dropped it to 1-3 at some point.

PeaceSleeper wrote:There is no other provider or user accessible parameter related to inspiration timing,

Is there anything referring to max IPAP time? I'm pretty sure there is a setting, but they definitely call it something different on their other BiPAPs...unless they have it preset at 3.0 seconds, unadjustable. It was an option on the regular Synchrony too, which wasn't a BiPAP ST. There is some sort of max time it can stay at IPAP...its just if its adjustable or not.

christinequilts wrote:

Snoredog wrote:
WHAT is the name of the parameter where it lists the 200-400msec values?

It gets confusing when they switch measurement units from brand to brand & even sometimes within brands over time, along with all the names for various settings too. It use to be if someone was talking about mSeconds, I knew they were talking about Rise Time on a VPAP (or whatever ResMed actually calls it), if they said 1-6, it was a Resprironic's BiPAP rise time, but I guess they dropped it to 1-3 at some point.

PeaceSleeper wrote:There is no other provider or user accessible parameter related to inspiration timing,

Is there anything referring to max IPAP time? I'm pretty sure there is a setting, but they definitely call it something different on their other BiPAPs...unless they have it preset at 3.0 seconds, unadjustable. It was an option on the regular Synchrony too, which wasn't a BiPAP ST. There is some sort of max time it can stay at IPAP...its just if its adjustable or not.

Just to demonstrate how much things can vary, I set the bilevel to be fixed las night but use biflex with max relief at 3. IPAP 10, EPAP 6. I imagine I could keep cranking up IPAP until I get fewer hypopneas, but at some point hit a diminishing return.